4 * \brief This file contains CMAC definitions and functions.
6 * The Cipher-based Message Authentication Code (CMAC) Mode for
7 * Authentication is defined in <em>RFC-4493: The AES-CMAC Algorithm</em>.
10 * Copyright (C) 2015-2018, Arm Limited (or its affiliates), All Rights Reserved
11 * SPDX-License-Identifier: Apache-2.0
13 * Licensed under the Apache License, Version 2.0 (the "License"); you may
14 * not use this file except in compliance with the License.
15 * You may obtain a copy of the License at
17 * http://www.apache.org/licenses/LICENSE-2.0
19 * Unless required by applicable law or agreed to in writing, software
20 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
21 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
22 * See the License for the specific language governing permissions and
23 * limitations under the License.
25 * This file is part of Mbed TLS (https://tls.mbed.org)
28 #ifndef MBEDTLS_CMAC_H
29 #define MBEDTLS_CMAC_H
31 #if !defined(MBEDTLS_CONFIG_FILE)
34 #include MBEDTLS_CONFIG_FILE
43 /* MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED is deprecated and should not be used. */
44 #define MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED -0x007A /**< CMAC hardware accelerator failed. */
46 #define MBEDTLS_AES_BLOCK_SIZE 16
47 #define MBEDTLS_DES3_BLOCK_SIZE 8
49 #if defined(MBEDTLS_AES_C)
50 #define MBEDTLS_CIPHER_BLKSIZE_MAX 16 /**< The longest block used by CMAC is that of AES. */
52 #define MBEDTLS_CIPHER_BLKSIZE_MAX 8 /**< The longest block used by CMAC is that of 3DES. */
55 #if !defined(MBEDTLS_CMAC_ALT)
58 * The CMAC context structure.
60 struct mbedtls_cmac_context_t
62 /** The internal state of the CMAC algorithm. */
63 unsigned char state[MBEDTLS_CIPHER_BLKSIZE_MAX];
65 /** Unprocessed data - either data that was not block aligned and is still
66 * pending processing, or the final block. */
67 unsigned char unprocessed_block[MBEDTLS_CIPHER_BLKSIZE_MAX];
69 /** The length of data pending processing. */
70 size_t unprocessed_len;
73 #else /* !MBEDTLS_CMAC_ALT */
75 #endif /* !MBEDTLS_CMAC_ALT */
78 * \brief This function sets the CMAC key, and prepares to authenticate
80 * Must be called with an initialized cipher context.
82 * \param ctx The cipher context used for the CMAC operation, initialized
83 * as one of the following types: MBEDTLS_CIPHER_AES_128_ECB,
84 * MBEDTLS_CIPHER_AES_192_ECB, MBEDTLS_CIPHER_AES_256_ECB,
85 * or MBEDTLS_CIPHER_DES_EDE3_ECB.
86 * \param key The CMAC key.
87 * \param keybits The length of the CMAC key in bits.
88 * Must be supported by the cipher.
90 * \return \c 0 on success.
91 * \return A cipher-specific error code on failure.
93 int mbedtls_cipher_cmac_starts( mbedtls_cipher_context_t *ctx,
94 const unsigned char *key, size_t keybits );
97 * \brief This function feeds an input buffer into an ongoing CMAC
100 * It is called between mbedtls_cipher_cmac_starts() or
101 * mbedtls_cipher_cmac_reset(), and mbedtls_cipher_cmac_finish().
102 * Can be called repeatedly.
104 * \param ctx The cipher context used for the CMAC operation.
105 * \param input The buffer holding the input data.
106 * \param ilen The length of the input data.
108 * \return \c 0 on success.
109 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA
110 * if parameter verification fails.
112 int mbedtls_cipher_cmac_update( mbedtls_cipher_context_t *ctx,
113 const unsigned char *input, size_t ilen );
116 * \brief This function finishes the CMAC operation, and writes
117 * the result to the output buffer.
119 * It is called after mbedtls_cipher_cmac_update().
120 * It can be followed by mbedtls_cipher_cmac_reset() and
121 * mbedtls_cipher_cmac_update(), or mbedtls_cipher_free().
123 * \param ctx The cipher context used for the CMAC operation.
124 * \param output The output buffer for the CMAC checksum result.
126 * \return \c 0 on success.
127 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA
128 * if parameter verification fails.
130 int mbedtls_cipher_cmac_finish( mbedtls_cipher_context_t *ctx,
131 unsigned char *output );
134 * \brief This function prepares the authentication of another
135 * message with the same key as the previous CMAC
138 * It is called after mbedtls_cipher_cmac_finish()
139 * and before mbedtls_cipher_cmac_update().
141 * \param ctx The cipher context used for the CMAC operation.
143 * \return \c 0 on success.
144 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA
145 * if parameter verification fails.
147 int mbedtls_cipher_cmac_reset( mbedtls_cipher_context_t *ctx );
150 * \brief This function calculates the full generic CMAC
151 * on the input buffer with the provided key.
153 * The function allocates the context, performs the
154 * calculation, and frees the context.
156 * The CMAC result is calculated as
157 * output = generic CMAC(cmac key, input buffer).
160 * \param cipher_info The cipher information.
161 * \param key The CMAC key.
162 * \param keylen The length of the CMAC key in bits.
163 * \param input The buffer holding the input data.
164 * \param ilen The length of the input data.
165 * \param output The buffer for the generic CMAC result.
167 * \return \c 0 on success.
168 * \return #MBEDTLS_ERR_MD_BAD_INPUT_DATA
169 * if parameter verification fails.
171 int mbedtls_cipher_cmac( const mbedtls_cipher_info_t *cipher_info,
172 const unsigned char *key, size_t keylen,
173 const unsigned char *input, size_t ilen,
174 unsigned char *output );
176 #if defined(MBEDTLS_AES_C)
178 * \brief This function implements the AES-CMAC-PRF-128 pseudorandom
179 * function, as defined in
180 * <em>RFC-4615: The Advanced Encryption Standard-Cipher-based
181 * Message Authentication Code-Pseudo-Random Function-128
182 * (AES-CMAC-PRF-128) Algorithm for the Internet Key
183 * Exchange Protocol (IKE).</em>
185 * \param key The key to use.
186 * \param key_len The key length in Bytes.
187 * \param input The buffer holding the input data.
188 * \param in_len The length of the input data in Bytes.
189 * \param output The buffer holding the generated 16 Bytes of
190 * pseudorandom output.
192 * \return \c 0 on success.
194 int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_len,
195 const unsigned char *input, size_t in_len,
196 unsigned char output[16] );
197 #endif /* MBEDTLS_AES_C */
199 #if defined(MBEDTLS_SELF_TEST) && ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_DES_C) )
201 * \brief The CMAC checkup routine.
203 * \return \c 0 on success.
204 * \return \c 1 on failure.
206 int mbedtls_cmac_self_test( int verbose );
207 #endif /* MBEDTLS_SELF_TEST && ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
213 #endif /* MBEDTLS_CMAC_H */